<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    
</body>
<script>
    const arr=[1,2,3]
    console.log(arr instanceof Array);

    const str='1'
    console.log(str instanceof String);

    const obj={name:'hui'}
    console.log(obj);
</script>
</html>